Artificial Cornea

The cornea is the transparent, outermost part of the eye that serves as a refractive element in the visual pathway. It consists of three major cellular layers: a protective epithelium, stroma made mostly of highly organized collagen, and an endothelium that serves to maintain water balance and transparency. Disease or damage to these layers can lead to blindness that requires a corneal transplant. While human donor transplants are the standard treatment for corneal blindness, the complications and limitations inherent in them have prompted development of synthetic corneal substitutes. An artificial cornea, or keratoprosthesis (Kpro), has great potential to benefit millions worldwide who are blind due to corneal disease. Although Kpros have been available for many years in various forms, the fabrication of synthetic stromal equivalents with the transparency, biomechanics, and regenerative capacity of human donor corneas remain a formidable challenge. In our collaboration with the Department of Chemical Engineering, Professor Curtis Frank and his students have developed novel double networks hydrogels with great potential for replacing corneal stroma. Despite their high water content (60-90%), these blended polymers are extremely resistant to wear and fracture, with tensile strengths up to 20 times stronger than their component single networks alone. Moreover, these materials are optically clear and highly permeable to glucose, the primary nutrient for the cells of the cornea. Using photopatterning techniques, we have developed ways to covalently tether the surfaces of these hydrogels with cell adhesion-promoting moieties, and to alter their three-dimensional structure to encourage bulk tissue integration. In preliminary work, we have shown these materials can facilitate corneal epithelial cell adhesion and have demonstrated that they are biocompatible in an animal model. Our ongoing work entails further characterization of double network properties, the cellular response to them both in vitro and in vivo, and the fabrication of tissue-integrable device prototypes.